TY - JOUR
T1 - Microstructure and mechanical properties of Cu-3 at.% Ti alloy aged in a hydrogen atmosphere
AU - Semboshi, Satoshi
AU - Nishida, Tomoya
AU - Numakura, Hiroshi
N1 - Funding Information:
The authors thank Dr. K. Takada (Tohoku University) for hydrogen analysis, Professor T. Takasugi (Osaka Prefecture University), Professors S. Hanada, T.J. Konno and N. Masahashi (Tohoku University), and Professor R. Kirchheim (The University of Göttingen) for useful discussion and comments. This work was partly performed under the inter-university co-operative research program of the Institute for Materials Research of Tohoku University, and was supported by Inamori Foundation and by Japan Research Institute for Advanced Copper-based Materials and Technologies.
PY - 2009/8/20
Y1 - 2009/8/20
N2 - The microstructure of Cu-3 at.% Ti alloy aged at 773 K in a hydrogen atmosphere of 0.37 MPa has been investigated, together with hardness and tensile strength. At the early stage of aging, needle-shaped α-Cu4Ti particles precipitate finely in a similar manner to the case of conventional vacuum-aging. On further aging, some α-Cu4Ti precipitates are extended, while others are replaced by δ-TiH2 precipitates. The precipitation of titanium hydride reduces the concentration of Ti in the matrix more efficiently than aging in a vacuum. The yield strength first rises, but falls on further aging. This is due to the microstructural evolution: α-Cu4Ti particles first form and grow, but then diminish because of the formation of titanium hydrides. Elongation to fracture, as well as the electrical conductivity, is promoted by long-time aging in the hydrogen atmosphere, reflecting the reduced Ti concentration in the matrix.
AB - The microstructure of Cu-3 at.% Ti alloy aged at 773 K in a hydrogen atmosphere of 0.37 MPa has been investigated, together with hardness and tensile strength. At the early stage of aging, needle-shaped α-Cu4Ti particles precipitate finely in a similar manner to the case of conventional vacuum-aging. On further aging, some α-Cu4Ti precipitates are extended, while others are replaced by δ-TiH2 precipitates. The precipitation of titanium hydride reduces the concentration of Ti in the matrix more efficiently than aging in a vacuum. The yield strength first rises, but falls on further aging. This is due to the microstructural evolution: α-Cu4Ti particles first form and grow, but then diminish because of the formation of titanium hydrides. Elongation to fracture, as well as the electrical conductivity, is promoted by long-time aging in the hydrogen atmosphere, reflecting the reduced Ti concentration in the matrix.
KW - Age-hardening
KW - Aging
KW - Cu-Ti alloy
KW - Hydrogen
KW - Mechanical properties
KW - Precipitation
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U2 - 10.1016/j.msea.2009.03.047
DO - 10.1016/j.msea.2009.03.047
M3 - Article
AN - SCOPUS:67649392461
SN - 0921-5093
VL - 517
SP - 105
EP - 113
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
IS - 1-2
ER -